Compound metal body and process of producing same.



PATENTED JULY 2l, 1908.

Oum/695911,66?

ATTOR N EYS J. F. MONNOT. COMPOUND METAL BODY AND PROCESS 0F PRODUCING SAME.

APPLICATION FILED APR.13.1`907.

UNITED sTATEs PATENT oEEIcE.

.IOlIN F. MONNOT, F

NEW YORK, N.Y.,ASSIGNOR TO DUPLEX METALS COMPANY, NEW YORK, N. Y., A CORPORATION OF NEW YORK.

NQ. soaess.

Specification of Letterslatentv.

Patented July 21, 1908.

Application vilezl April 13, 1907. Serial No. 367,986.

To all whom it may concern.'

Be it known that I, JOHN F. MONNOT, a citizen of the United States, residing at New York, in the county of New York and State of New York,.have invented certain new and useful Improvements in Com ound Metal Bodies and Processes of Pro ucing Same; and I do hereby declare the followin to be a full, clear, and exact description of t esame, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to reinforced gold and processes of preparing the same and consists in metal articles composed of layers of gold permanently united to backing layers of harder and stronger metals, and in particular to the ferrous metals, and also in a Arocess of firmly and permanently uniting go d to such other metals by a union in the nature of a weld union; all as more fully hereinafter set forth and as claimed.

Steel and the ferrous metals generally d not readily unite to the Wholly unlike metal gold, either by cast-on unions or even by electroplating, and gold and steel are seldom if ever directly united, despite the manifest advantages which such a combination of metals would offer. In electroplating, it is generally considered necessary to cover the iron or steel with a preliminary coating of copper and then deposit the gold on the co per. Mercurial gilding, formerly frequenti) used, has now gone out of use because of its expense, dangerous nature and generally unsatisfactory results. The film roduced, while of course fitting snugly in a the sur-y face irregularities of the steel and therefore adhering, hasno lreal cohesion and readily strips, the stripping being much facilitated by the fact that the coating is porous and permits permeation of moisture and corrosive gases to the underlying corrodible metal. Electrolytic coatings are also porous and readily strip, having no coherence with the base metal. And lin all these prior methods, it has been necessary to produce an article of the finished sha e and then plate or otherwisecoat with t e gold, the coatings having n'o such union with theysteel as would ermit coatingan ingot or other intermediate article and subsequent coextending to form the finished article.

It is the object of the present invention to devise a method of producing unions between gold and steel, preferably autogenous in character, which shall be firm, permanent and of the character of a Weld, ermitting indefinite coextension of the ]oined metals without separation and with preservation of the same relative thickness of such 'oined metals throughout the working, an producing metal articles of novel character.

I have `discovered that the lack of affinit between steel and gold which subsists at a l common temperatures and which renders diflicult their direct unionby any lof the known processes, though also existing at the common casting temperature of gold, disappears when the gold is raised to a tem erature much above its melting Cpoint. hen steel is presented ina clean an non-oxidized condition to gold in this state which, for lack of lanother name, I have termed the supermolten condition the steel is readily wetted by the fluid old and unites with it in some manner not c early understood, so that after solidification of the' gold, the two metals will be found autogenously and permanently unitedby a union in the nature of a weldunion, resistin rupture by cutting tools,

flexure'or sud en changes in temperature.

For most mechanical purposes, the two `joined metals will be found to be capable of iinity possessed by the igh melting metals at temperatures much above their melting oints, appears to be generic and in Patent No. 853,716, dated May 14th, 1907, I have described and broadly claimed processes of unitin metals based 0n this fact.

Gol melts at about 19.50 Fahrenheit and the supermolten temperature is about five hundred or more `degrees above that temperature. Its alloys with co per, etc., such as coin gold, melt at much ower temperatures but a similar elevation of temperature above the melting point, whatever it may be, also brings them to a supermolten condition. For the purposes of the resent invention, either pure gold or its a oys may be employed. Gold so attached to steel, being put on in the fluid condition, shares in the peculiarity of iuids and set iiuids in bein poreless, and as subsequent coextension o the joined metals further compacts the old, obliterating blow-holes, cavities and the ike, in the finished article, the coating is absolutely impervious to fluids and gases, in this "ing, and the like. his eculiar mutual af res ect being wholly unlike the usual firegil ings and electroplatings.

In cases where it is deemed preferable to work with at least part of the gold at a less temperature, the same character of coating may bedsecured by the use of an expedient which consists in first filming the steel by contact with supermolten gold to form a superficial coating and then casting against the so-treated'surface, gold at a more convenient casting temperature. Or the filmed surface may, though less' advantageously,

' have solid or softened gold welded to it by mechanical force. Still another expedient is to substitute a film of co per in the initial treatment of the steel, dippmg the steel into a bath of supermolten copper for this purproducer gas, or other non-oxidizing gas,

transfer the casing over the bath of vsupermolten gold, lower the ingot into the bath a sufficient time-ordinarily a few seconds sufiices-to cover the steel with a film of coher- 'ing gold, withdraw it into the casing, move the casingl over an ingot mold, transfer the ingot'to t e mold and then cast about it, or

. in contact with it, sufficient gold at ordinary casting temperature, to form the desired thickness of coating. Or, after di ping the ingot into the supermolten gold, tliie casing may then be lowered around it, segregating fa layer of the supermolten gold in immediate contact with the ingot, a bottom plate aflixed and the casin then' withdawncarrying -the ingot and the ayer of gold.

Ordinarily the-ingot should be heated, but not to the full supermolten temperature of the gold. Upon t en contacting it with the supermolten gold while the superficial layers of the steel ac uire the necessary temperature for the union, this temperature persists but momentarily, the heat soaking inward-in the ingot. Where the su ermolten gold is relied upon toform the fuli thickness of the coating, the temperature of the layer of gold is also quickly reduced by conduction outward through the mold walls. It is generally quite important that the two metals should not be long in. contact at the supermolten temperature, thereby avoiding detriment to either by solution or corrosion of the other.

It may then have the' sectional view of one form of a At the supermolten temperature the gold is, as stated, quite reactive, and it is therefore better not to prolong contact.

As to the natureof the stated activity at the supermolten temperature or as to the nature of the union which is formed, this is not definitely settled. It may be that the two metals superficially alloy, and certain phenomena seem to indicate this, forming a very thin intermediate alloy-film, said al- 7 loy being either a physical or chemical mixture. Or Ait may be that the gold simply perfectly and molecularly wets the surface of the steel, forming a union therewith which is in the nature of a molecular interpenetration or interlocking in which the molecules of the` two metals cohere as the like molecules of each cohere to each other. But whatever the cause, the fact of a perfect union exists; a true cohesion as distinguished from a mere adhesion or sticking together. Where it is desired to work with the gold at a lower or ordinary 'casting temperature, the steel may be'film coated by a dip into supermolten copper or co per at a temperature of several hundred egrees above its melting oint or ordinary casting temperature. Wit the coppered surface so prepared, in which the copper coheres to the steel, gold at an ordinary casting temperature may be now applied.

In the accompanying illustrations I have shown, more or less dia ammatically certain material'and means a apted to perform the stated process. f

In said drawingsz-Figure 1 represents a paratus for carrying out the said process. 1g. 2 shows in detail section the construction of bottom plate and lower portion of casing preferably employed'. Fig. 3 shows a sectional view of another form of casing which may be em'- ployed.

In Fig. 1, 1 is a preliminary heating chamber for the ingot or-core, 2 a furnace for heat- 11C ing a' crucible 3, containing a body of supermolten coating metal, and 4 designates a second crucible, which may or may not be used, as desired.

5 designates a power hoist, here shown as 115 an electrical hoist, mounted on a suitable track so that it can be moved from place to place; and from said hoist is suspended, by means of a porter bar 6, the ingot 7, which is the object to be coated. Said ingot is shown 120 surrounded by a casing 8 having an internal diameter slightly larger than the external diameter of the ingot, and to said casing is connected a pipe 9, a portion of which is flexible, said pipe provided with a three-way valve 10. 1:25 This pipe and the valve 10 are provided for supplying tothe casing, when desired, an atmos here of indifferent or neutral gas, such asv pro ucer gas. Casing 8 has a'weiglited head 1 1 which insures that when the casing is low- 130 `matching a corresponding groove 15, in the lower edge of the casing, and adapted to coact with said groove to make a tight joint. For raising and lowering the casing 8 with respect to the ingot 7, a s ecialhoist 1f,sus pended like porter bar 6 om hoist 5, 1s provided. It has, in the form shown, two windin drums 17 upon which are wound two ca les 18 connected to opposite sides of the casing, so that said casing may be raised an lowered truly vertically.

I customarily provide the crucibleywith a loose removable cover 19, which cover is designed to exclude air from the molten metal so far as possible, and is removed only when and so long as necessary to lower an ingot and casing into the crucible, or to inspect the molten metal, or for similar reason. To further exclude air from the surface of the molten metal, I cover so much of its surface as possible with a layer of charcoal, a ring 20 of refractory material which fioats on the surface of the molten metal serving to maintain a clear space in the center for the passage of the ingot and casing.

As an alternative to the above described apparatus for carrying out my process, I may use that shown in Fig. 3, which is much the same as that above described except that the casing 8 is provided with inlets 23 in its sides, said inlets arranged to be closed at will by a sliding shield or valve 24.' In carrying out the process with this apparatus the casing without the bottom plate 12 thereon is placed over the heating chamber 1, said casing being at'the time filled with a protective atmosphere as above described, and the porter bar is lowered down through the casing, secured to the ingot or core to be coated and raised up into said casing again with the said ingot or core.' The casing with the core7 Within it, is then moved to one side, the bottorn plate 12 applied, and/then the casing is moved over the crucible 3 containing supermolten coating metal, and is lowered into said supermolten metal; the valve or closure 24 being raised as the openings 2 3fcome to the surface of the molten metal so that said casing fills through said openings 23. The casing with ingot and molten metal within it is then raised and the molten metal allowed to cool as before'. In carrying out the process in this way, thel protective atmosphere within the casing when the'iilling holes 23 are open, protects the surfacejof the ingot and the molten metal which enters the casing against oxidation; and in fact no'. air can enter the casing, because the holes 23 are submerged in the molten metal almost instantly after the closure 24 is raised, and during the possible brief instant 'while said. openings are open but not completely submerged the outrush of gas from the casing will prevent the entrance of air.

To hasten the filling of the casing with molten metal, a'nd to prevent trapping of gas in the molten metal as it solidifies, I preferably apply suction to the outlet 25 of valve 10,

, having iirst set said valve so as to cut off the entrance ofgas and to place outlet 25 in commumcatlon wlth the interior of the casing.

This isdone, however, only after the molten metal'has commenced-to iiow in. And when -necessary or expedient, I reduce the fluid pressure upon the joint between the bottom plate and casing, While raising either the cas# ing shown in Fig. 1 or the casing shown in Fig. 3, by applylng suction to the outlet 25 of valve 10, v

The coated ingot produced in either of the ways above described is usually worked, as. by rolling (either at once, or after submersion to a soaking heating to bring all the parts to a uniform temperature), to condense the metal of the coating and to extend it to shapes desirable for future working, such as bars, rods, and plates. In such extension the joined metals extend together without rupture of union and between them and the -inal article usually contains the same relative proportion of coating and base as the finished ingot.

The core or scribed in this specification need not be iron or steel, but for most purposes an iron or steel base or core will be preferred. Hence in certain of the following claims I specify steel as e properties of which are nearly identical base or ingot coated as 'de-` with those of mild steel) -and various compound steels, such as tungsten steel, titaniun steel, vanadium steel, chrome steel, nickel steel, manganese steel, cobalt steel also substantially pure iron-i. e., the` chemical element Fe, substantially free from carbon and other metalloids orimpurities and modifying in edients.

the methods of uniting gold and iron or` steel above described, the excessively hiffh temperature of the abutting layers of unli e metals exists only temlpprarily as the: heat ofV the molten metal soa into the steel core, While the heat of the molten metal is translit ferred outwardly by the coolin of the casing walls, and no opportunity is a orded'for detl'lmental action upon either the maln body of the steel or that of the molten metal.

either metal, are only in the excessively thin jolmng layer between; and since, as already Such? changes as take place, or may take place, 1n

ex lained, I do not limit myself to any theory of Eflow' the union between the unlike metals takes place, therefore I do not assert positively, that when the operation is properly performed, any change of the two metals, or either of them, at the point of juncture, actually takes place. As previously explained, the time of contact of the steel and gold or other coating metal used, while such gold or other coating metal remains in the supermolten condition, is very brief, for long contact of the two metals with the gold or other coating metal in the very high reactive condition afforded by thesu 'ermolten tem erature, would of course be detrimenta to both. By limitin to a few seconds the period of contact o the metals while one of them is in the supermolten condition, I limit to extreme thinness the joining layer of alloyed, mixed, interpenetrating, or otherwiseunited metals.

The steel coated in any of the foregoing ways possesses a cohering layer or stratum of gold which can be drawn, beaten or rolled together with it at ordinary steel working temperatures without parting, even in the finest of wire, or in thin leaf. In an ingot so clad, a cutting tool, such as a cold chisel, refuses to discover or follow the line of union, veering off into the softer metal and heating and sudden quenching do not separate the joined metals.

Usin very soft, pure iron, such as is obtained Iiy the Tro enas process, or in'blowing melted iron til practically all carbon and metalloids are removed, for the in ot and coating with a comparatively thin ayer of gold, a compound metal body is obtained which will stand extension into the thinnest of gold leaf. Because of the opacity of the iron, the merest film of gold serves in the finished article. Such pure soft iron used as a core gives metal well adapted for jewelers use for making chains, rings, filled watch cases and like purposes, after rolling or drawing down to the desired. dimensions. When cut in the ordinary manner to form finished articles, the iron of course shows at exposed edges but by the use vof .certain means and expedients, these cut edges may also have the core metal concealed. As set forth in my application filed March 2, 1906, Sr. No. 303,916, I have found that by cutting such compound metal, as for example a plate of steel cored gold, with cutters or nippers with rounded or obtunded ed es, giving a pinchin cut, the core metal may e ruptured efore t e coating metal and the latter, so to speak, fiowed down over its exposed edge. Treatment with ordinary burnishing tools serves to complete the union of" the metal so extended over the edge.

With a somewhat stiffer metal than the may be made which are substantially safe against rupture by pickpockets and thieves. Gold clad steel plates are eminently suitable for acid stills. The list of uses to whlch my new gold clad steel may be applied is of course practically endless, and those cited are merely particular examples.

Instead of applying the coating in a single operation, as above described, I may apply it in two operations, film-coating the ingot 7 by immersing it momentarily in the supermolten metal in crucible 3 and then, without lowering the casing into the supermolten metal, withdrawing the ingot, now covered with a thin film-coating formed by the action of the supermolten metal, back into the casing, movlng said casing over the crucible 4, the molten metal in which is preferably at ordinary lcasting temperature or thereabout, applying the bottom late to the ingot, lowering said ingot into t e metal of bath 4 and thereafter lowering the casing and so confining against the film-coated surface a layer of the metal from bath 4, and then withdrawing the casing with its 'contents from the molten metal and permitting the molten metal within it to solidify. Or, instead of using the apparatus of Fig. 1, that of Fig. 3 may be used; the conse uent variation in the procedure just descri ed being obvious.

In case the o eration is carried on in two ste s instead o one, the supermolten metal of ath 3 will ordinarily be 'some cheaper metal than gold which has the power of combining with iron or steel or other metal ofnated; which, if the supermolten metal be a precious metal, such as gold or silver, may add materially to the'cost of the process, because of the Waste of expensive metal involved. By employing a less expensive metal, such ascop er, the ossible'loss due to contaminationoft emeta is greatlyreduced. Gold at ordinary casting temperature will unite readily with a copper-coating formed from supermolten copper, so as to be as inseparable from the copper as the copper is from the iron or other base; and the thickness of the copper layer may be so slight as to be almost inappreciable, and quite inappreciable in the extended product.

I intend the term gold as used herein to include such alloys or mixtures as are commonly termed gold, even thou h the proportion of other metal be relative y great.

In application for Letters Patent filed April 17, 1907, Sr. No. 368,770, I have of makin claimed broadly a rocess` of producing comound or clad meta articles comprising coating a surface of a metal base by contact with a supermolten mass of an unlike metal and then contactin the coating so formed with a molten mass o a third metal Aand causing a layer thereof to solidify thereon. In an application filed April 24, 1907, Sr. No. 369,997,.

have claimed a rooess of forming compound or clad meta articles comprising contacting a surface of one metal with a supermolten mass of an unlike metal and confining a'portion of the metal from such supermolten mass, of substantial thickness, in contact with such surface and causing it to solidify thereon. In an application filed June 19, 1908, Sr. No. 439,284, I have claimed cornpound or clad metal articles comprising a coating of copper, silver, gold, aluminum and like metals, alloyed With ferrous metals, Weld-united to ferrous metals, and a process such articles. Therefore I do not claim-suc inventions in this case.

What I claim is 1. The process of making compound metal bodies which consists in contactmga ferrous metal base With a non-ferrous metal at a temperature much above its melting point. and

uniting a layer of a metal comprising gold to molten mass of a third metal, thereby forming on said base a coating, and uniting to said coating a layer of a metal comprising old.

4. The process of making compoun metal bodies Which consists in uniting a ferrous metal and a metal comprisingr gold by contacting with the surface of said base a supermolten mass `ofcopper, thereby forming on said base a coating, and uniting to said coating a layer of a metal comprising gold.

5. The rocess of making compound metal bodies which consists in contacting a ferrous metal base With a non-'ferrous metal maintained at a temperature much above its melting temperature and thereafter casting molten gold against the treated base.

6. The rocess of making compound metal bodies which consists in contacting a ferrous metal base With copper maintained at a reactive temperature much above its melting temperature and thereafter casting molten gold against the treated base.

7. The process of making compound metal bodies which consists in uniting a metal com- 1ng a body of such unlike metal With a supermolten mass of athird metal and then casting molten gold-comprising metal against such body. f

8. As a new article of manufacture, a compound metal body comprising a ferrous metal base and a poreless layer of a metal comprising old united thereto by a union indisseverab e by cutting toolsl or temperature changes.

9. As a new article of manufacture gold clad steelcomprisin a baseof steel having a poreless layer of go d united thereto by an intermediate layer of a third metal of' high meltin point;

10. a new article of manufacture gold clad steel comprisin a base of steel having a poreless layer of go d united thereto by an intermediate layer of co per.

In testimony whereof affix my signature, in the presence of two Witnesses.

. Y JOHN F. MONNOT.

Witnesses:

J. F. KINDER, H. M. MARBLE. 

